缺血陛脑损伤诱导大鼠巢蛋白表达的实验研究

Experimental study on inducement of ischemic brain injury to nestin expression of rats

目的探讨缺血性脑损伤对内源性神经干细胞增殖、迁移的影响。方法选用健康雄性SD大鼠62只,随机分为正常组(6只)、脑缺血10 min再灌流1、3、5、7、10、15、20d组(简称手术组,每时间点6只)、假手术对照组(14只,每时间点2只),参照Pulsinelli-Brierley方法制作短暂性全脑缺血动物模型;用SABC免疫组化法显示巢蛋白(nestin)阳性细胞;光镜下观察nestin阳性细胞的形态学变化并计数,半定量分析脑缺血损伤后内源性神经干细胞增殖、迁移的变化过程。结果手术组的nestin阳性细胞在缺血再灌流24h后表达增多,7～10d到高峰,15 d时仍有显著表达:在室管膜下区的nestin阳性细胞有向皮质、海马迁移的迹象。结论缺血性脑损伤能诱导内源性神经干细胞增殖,这可能对脑损伤后的修复发挥作用。

Objective To probe into the effects of ischemic brain injury on proliferation and migration of endogenous neural stem cells （NSCs）. Methods A total of 62 healthy male SD rats were randomly divided into the normal group （n=6）, operation group, with 6 rats at each time point, 42 rats in total （reperfusion at 1, 3, 5, 7, 10, 15 or 20 d after 10 min cerebral ischemia）, and sham-operated control group （n=lg, 2 rats at each time point）. The rat models with transient global cerebral ischemia were established by Pulsindli-Brierley＇ s four-vessel occlusion; SABC immunohistochemistry was employed to show neuroepithelial stem cell protein （nestin） positive cells; the morphological changes of nestin positive cells were observed under the optical microscope and their number was counted, for the semi-quantitative analysis of the change process in proliferation and migration of endogenous NSCs after ischemic brain injury. Results The expression ofnestin positive cells in the operation group increased 24 h later after ischemia-reperfusion, achieved its climax between 7-10 d and was still obvious at 15 d; there was evidence that nestin positive cells migrated lYom the SVZ to the cortex or hippocampus. Conclusion Ischemic brain injury may induce the proliferation of endogenous NSCs, which might exert effects for the recovery of brain injury.